﻿#region 命名空间

using System;
using System.Collections.Generic;
using System.Data;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.SessionState;
using System.Drawing;
using System.Text;
using WinnerCMS.Common;

#endregion

namespace WinnerCMS.WebUI
{
    public class PassCode : IHttpHandler, IRequiresSessionState
    {
        public void ProcessRequest(HttpContext context)
        {
            context.Response.Expires = 0;
            context.Response.CacheControl = "no-cache";
            context.Response.Cache.SetCacheability(HttpCacheability.NoCache);


            var code = CreateVerifyCode(); //取随机码
            CreateImageOnPage(code, context); // 输出图片

            //Response.Cookies.Add(new HttpCookie("CheckCode", code.ToUpper()));// 使用Cookies取验证码的值

            if (context.Request["Action"] == null)
            {
                context.Session["VNum"] = code;
            }
            else
            {
                context.Session["Admin"] = code;
            }
        }

        #region 验证码长度

        private int length = 4;

        /// <summary>
        ///     验证码长度
        /// </summary>
        public int Length
        {
            get { return length; }
            set { length = value; }
        }

        #endregion

        #region 验证码字体大小

        private static int fontSize = 12;

        /// <summary>
        ///     验证码字体大小
        /// </summary>
        public static int FontSize
        {
            get { return fontSize; }
            set { fontSize = value; }
        }

        #endregion

        #region 边框补(默认1像素)

        private int padding = 2;

        public int Padding
        {
            get { return padding; }
            set { padding = value; }
        }

        #endregion

        #region 是否输出燥点(默认输出)

        private bool chaos = true;

        public bool Chaos
        {
            get { return chaos; }
            set { chaos = value; }
        }

        #endregion

        #region 输出燥点的颜色(默认灰色)

        private Color chaosColor = Color.LightGray;

        public Color ChaosColor
        {
            get { return chaosColor; }
            set { chaosColor = value; }
        }

        #endregion

        #region 自定义背景色(默认白色)

        private Color backgroundColor = Color.White;

        public Color BackgroundColor
        {
            get { return backgroundColor; }
            set { backgroundColor = value; }
        }

        #endregion

        #region 自定义随机颜色数组

        /// <summary>
        ///     自定义随机颜色数组
        /// </summary>
        public static Color[] Colors =
        {
            Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown,
            Color.DarkCyan, Color.Purple
        };

        #endregion

        #region 自定义字体数组

        /// <summary>
        ///     自定义字体数组
        /// </summary>
        public static Font[] Fonts =
        {
            new Font("Arial", fontSize, FontStyle.Bold | FontStyle.Italic),
            new Font("Verdana", fontSize, FontStyle.Bold | FontStyle.Italic),
            new Font("Comic Sans MS", fontSize, FontStyle.Bold | FontStyle.Italic)
        };

        #endregion

        #region 自定义随机码字符串序列(使用逗号分隔)

        /// <summary>
        ///     自定义随机码字符串序列(使用逗号分隔)
        /// </summary>
        public static string[] CodeSerial = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};

        #endregion

        #region 产生波形滤镜效果

        private const double PI = 3.1415926535897932384626433832795;
        private const double PI2 = 6.283185307179586476925286766559;

        /// <summary>
        ///     正弦曲线Wave扭曲图片
        /// </summary>
        /// <param name="srcBmp">图片路径</param>
        /// <param name="bXDir">如果扭曲则选择为True</param>
        /// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param>
        /// <param name="dPhase">波形的起始相位，取值区间[0-2*PI)</param>
        /// <returns></returns>
        public static Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
        {
            var destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);

            //// 将位图背景填充为白色
            var graph = Graphics.FromImage(destBmp);
            graph.FillRectangle(new SolidBrush(Color.White), 0, 0, destBmp.Width, destBmp.Height);
            graph.Dispose();

            double dBaseAxisLen = bXDir ? destBmp.Height : destBmp.Width;

            for (var i = 0; i < destBmp.Width; i++)
            {
                for (var j = 0; j < destBmp.Height; j++)
                {
                    double dx = 0;
                    dx = bXDir ? (PI2*j)/dBaseAxisLen : (PI2*i)/dBaseAxisLen;
                    dx += dPhase;
                    var dy = Math.Sin(dx);

                    // 取得当前点的颜色
                    int nOldX = 0, nOldY = 0;
                    nOldX = bXDir ? i + (int) (dy*dMultValue) : i;
                    nOldY = bXDir ? j : j + (int) (dy*dMultValue);

                    var color = srcBmp.GetPixel(i, j);
                    if (nOldX >= 0 && nOldX < destBmp.Width
                        && nOldY >= 0 && nOldY < destBmp.Height)
                    {
                        destBmp.SetPixel(nOldX, nOldY, color);
                    }
                }
            }

            return destBmp;
        }

        #endregion

        #region 生成校验码图片

        /// <summary>
        ///     生成校验码图片
        /// </summary>
        /// <param name="code"></param>
        /// <returns></returns>
        public Bitmap CreateImageCode(string code)
        {
            var fSize = FontSize;
            var fWidth = fSize + Padding;

            var imageWidth = (code.Length*fWidth) + 4 + Padding*2;
            var imageHeight = fSize*2 + Padding;

            using (var image = new Bitmap(imageWidth, imageHeight))
            {
                var g = Graphics.FromImage(image);

                g.Clear(BackgroundColor);

                var rand = new MyRandom();

                //给背景添加随机生成的燥点
                if (Chaos)
                {
                    var pen = new Pen(ChaosColor, 0);
                    var c = Length*10;

                    for (var i = 0; i < c; i++)
                    {
                        var x = rand.Next(image.Width);
                        var y = rand.Next(image.Height);

                        g.DrawRectangle(pen, x, y, 1, 1);
                    }
                }

                int left = 0, top = 0, top1 = 1, top2 = 1;

                var n1 = (imageHeight - FontSize - Padding*2);
                var n2 = n1/4;
                top1 = n2;
                top2 = n2*2;

                int cindex, findex;

                //随机字体和颜色的验证码字符
                for (var i = 0; i < code.Length; i++)
                {
                    cindex = rand.Next(Colors.Length - 1);
                    findex = rand.Next(Fonts.Length - 1);
                    var f = Fonts[findex];

                    using (Brush b = new SolidBrush(Colors[cindex]))
                    {
                        if (i%2 == 1)
                        {
                            top = top2;
                        }
                        else
                        {
                            top = top1;
                        }

                        left = i*fWidth;

                        g.DrawString(code.Substring(i, 1), f, b, left, top);
                    }
                }

                //画一个边框 边框颜色为Color.Gainsboro
                using (var PP = new Pen(Color.Gainsboro, 0))
                {
                    g.DrawRectangle(PP, 0, 0, image.Width - 1, image.Height - 1);
                }
                g.Dispose();

                //产生波形 
                return TwistImage(image, true, 3, 4);
                ;
            }
        }

        #endregion

        #region 将创建好的图片输出到页面

        /// <summary>
        ///     将创建好的图片输出到页面
        /// </summary>
        /// <param name="code"></param>
        /// <param name="context"></param>
        public void CreateImageOnPage(string code, HttpContext context)
        {
            using (var ms = new System.IO.MemoryStream())
            {
                var image = CreateImageCode(code);

                image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);

                context.Response.ClearContent();
                context.Response.ContentType = "image/Jpeg";
                context.Response.BinaryWrite(ms.GetBuffer());


                image.Dispose();
            }
        }

        #endregion

        #region 生成随机字符码

        /// <summary>
        ///     生成随机字符码
        /// </summary>
        /// <param name="codeLen"></param>
        /// <returns></returns>
        public string CreateVerifyCode(int codeLen)
        {
            if (codeLen == 0)
            {
                codeLen = Length;
            }

            var code = new StringBuilder();

            var randValue = -1;

            var rand = new Random(unchecked((int) DateTime.Now.Ticks));

            for (var i = 0; i < codeLen; i++)
            {
                randValue = rand.Next(0, CodeSerial.Length - 1);

                code.Append(CodeSerial[randValue]);
            }

            return code.ToString();
        }

        /// <summary>
        ///     生成随机字符码
        /// </summary>
        /// <returns></returns>
        public string CreateVerifyCode()
        {
            return CreateVerifyCode(0);
        }

        #endregion

        public bool IsReusable
        {
            get { return false; }
        }
    }
}